1. Field of the Invention
The present invention relates to a circuit for controlling an electronic ballast IC to drive a high intensity discharge lamp.
2. Description of the Related Art
The IR2157-1 IC is a ballast IC manufactured by International Rectifier Corporation of El Segundo, Calif., and is described and claimed in U.S. application Ser. No. 09/225,635, filed Jan. 5, 1999, now U.S. Pat. No. 6,211,623 the disclosure of which is herein incorporated by reference. The IR2157-1 IC operates in accordance with a state diagram to switch between various phases including strike, pre-heat, run, overtemperature, etc. External circuitry and selected components are used to set the operating frequency of the lamp and other parameters.
It would be desirable to provide additional external circuitry, which operates in conjunction with the above-mentioned external circuitry, for striking the lamp up to 20 times or until the lamp is lit.